TRAP OF PONTESFORD HILL AND ADJACENT ALTERED ROCKS. 263 



and composed of compact felspar rocks, very like those of the Wrekin and Caradoc, and passes 

 into greenstone. It forms a separate low ridge, divided from the higher quartz rock of the Stiper 

 Stones by a very narrow valley filled with much local angular detritus. 1 further detected one or 

 two other mounds of trap on the eastern side of the axis of the Stiper Stones near Linley Hall. 

 One of these on the left bank of the brook, is a patch of fine crystalline greenstone. Another is con- 

 siderably developed on the right bank in the wooded hills called the Knolls, which form a part of 

 the beautiful and diversified grounds of Mr. More. It is an amygdaloid, consisting of kernels of 

 quartz and green earth in a base of dark purple-coloured granular felspar, and passing from granular 

 into compact felspar, with crystals of common felspar and sometimes small grains of iron pyrites. 

 These hills of trap range close up to the quartz rock of the Stiper Stones as prolonged through the 

 Heathmont, and their juxtaposition to these altered rocks, both here and at the Calf Knolls, 

 must be borne in mind when we endeavour to explain in the next chapter the nature of the quartz 

 rock. 



This line of altered rock and trap on the east side of the Stiper Stones, or one parallel to it at a 

 very little distance, is traceable along the Habberley Valley to Pontesford Hill and Lyd's Hole. 



Between Kinnerton and Habberley the whole line of red and purple sandstone is much contorted, 

 and in parts so veined and indurated, particularly near Gatten Lodge, as to lose all traces of a 

 bedded rock. Where the bedding is discernible it has sometimes an angle of 80°, in other parts 

 vertical, the strike being generally 25° to 30° east of north, but in places north and south. The 

 veins contain carbonate of lime, sulphate of barytes, and traces of the grey and green ores of copper. 



Pontesford Hill. — In following the line of altered rocks above described to the north- 

 east, and passing by the hollow filled with coarse alluvial detritus in which the village 

 of Habberley stands, we reach the well-known and picturesque hill of Pontesford, which 

 with its associated rocks at Lyd's Hole, forms the chief trappean mass of the district. 

 This hill presents a bold projecting headland towards the vale of Shrewsbury, and from 

 its prominent position, easy access, variety of composition, and beauty of outline, merits 

 a special description. (See the form of this hill in the view, p. 81.) 



Nearly all the phenomena of the altered and veined rocks which have been detailed 

 as occurring on the south-western prolongation of this axis are here clearly exhibited, 

 the same appearances being apparent on the sides of Pontesford Hill; and in the narrow 

 gorge by which the Habberley brook finds its exit to the vale of Shrewsbury, particularly 

 on the sides of the rapids and waterfall of Lyd's Hole, we see in actual contact with 

 the concretionary trap, the purple and green sandstones, highly indurated, much veined, 

 in parts brecciated, and almost approaching to coarse jasper. Thin films of steatitic 

 matter or serpentine occasionally line the faces of altered rock, and the mica of the 

 sandstone has disappeared. Receding only a few hundred paces from these dykes and 

 shoulders of the Pontesford Hill, the sandstone, shale, and conglomerate, though in 

 vertical or highly inclined beds, have regained their usual characters, as may be seen in 

 the Oaks Wood, Plealy Banks, &c. 



Other veined and altered rocks adhere to the north-eastern face of Pontesford Hill ; and nume- 

 rous trials have been made in search of ores, which, though found in small nests and veins, have 



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